On July 30, 1864, during the siege of Petersburg, the Union army, led by Gen. George Meade (and under direct supervision of Lt. Gen. Ulysses S. Grant), exploded a mine in order to blow a gap in the Confederate defenses. Although this military strategy was successful in killing 278 Confederate soldiers instantly and caused massive confusion and disarray amongst the survivors who were unable to organize and fight for over fifteen minutes, the explosion created a massive hole in the earth that is still present to this day (3). The depression is 170 feet long, 120 feet wide and at least 30 feet deep, hence the name “the battle of the crater.” This explosion was the largest man made explosion at that time in history, and although there were no other explosions during the war that had such a devastating and lasting effect on the land, many military operations involved explosions and excavations of the earth that altered the environment. The construction of earthen entrenchments, dubbed earthworks, was widespread, particularly around Washington D.C. Some earthworks were said to be as extensive as five miles (39). These defenses were created by large-scale digging operations and lining of the ramparts with fallen trees (11). These massive passages dug in to the earth can change the erosion dynamics of the landscape, which can cause many ecological problems, such as the reduction of topsoil. Topsoil is important for the storage of water and nutrients in order for both native plant species and agricultural crops to grow productively. Earthworks and explosions can also disrupt habitat of fossorial species.
The digging of mass graves after battles also changed the structure and composition of the soil. One soldier recalls the creation of a mass grave, “in one corner I saw a large pile of arms and legs; many already dead were lying on the grass, with blankets thrown over them, while not far distant, in the woods, a party were engaged in digging long trenches for sepulture” (2). With over 620,000 deaths during the war these mass soldiers’ graves were common after battles (6). Mass graves can cause ground water contamination, and drastically change the soil’s structural and microbial characteristics (22). With that said, one positive aspects of large post-battle graves is that the absence of coffins and toxic fluids typically used for embalming actually allows the human remains to decompose in a way that makes the land more fertile, perhaps allowing the post-war battlegrounds to promote the growth of native plants that support wildlife (28).